模拟360手机卫士界面的滑动

package com.rsft.demo.ui360; import android.content.Context; import android.graphics.Canvas; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import android.widget.Scroller; public class FlatScrollViewGroup extends ViewGroup { public float mTouchX; public float mLastMotionX; public int mActivePointerId = -1; public Scroller mScroller; private boolean mIsScorlling; private ViewIndexChangeLinstener mViewIndexChangeLinstener; private int mCurrentViewIndex = 0; public FlatScrollViewGroup(Context context, AttributeSet attrs) { super(context, attrs); mScroller = new Scroller(context); ComponentContainer cc1 = new ComponentContainer(context); addView(cc1, 0); cc1.init(1); ComponentContainer cc2 = new ComponentContainer(context); addView(cc2, 1); cc2.init(2); ComponentContainer cc3 = new ComponentContainer(context); addView(cc3, 2); cc3.init(3); } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { int childLeft = 0; final int count = getChildCount(); for (int i = 0; i < count; i++) { final View child = getChildAt(i); if (child.getVisibility() != View.GONE) { final int childWidth = child.getMeasuredWidth(); child.layout(childLeft, 0, childLeft + childWidth, child.getMeasuredHeight()); childLeft += childWidth; } } } @Override public void computeScroll() { if (mScroller.computeScrollOffset()) { mTouchX = mScroller.getCurrX(); int scrollY = mScroller.getCurrY(); scrollTo((int) mTouchX, scrollY); postInvalidate(); } } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); final int widthMode = MeasureSpec.getMode(widthMeasureSpec); if (widthMode != MeasureSpec.EXACTLY) { throw new IllegalStateException( "Workspace can only be used in EXACTLY mode."); } final int heightMode = MeasureSpec.getMode(heightMeasureSpec); if (heightMode != MeasureSpec.EXACTLY) { throw new IllegalStateException( "Workspace can only be used in EXACTLY mode."); } final int count = getChildCount(); for (int i = 0; i < count; i++) { getChildAt(i).measure(widthMeasureSpec, heightMeasureSpec); } } @Override protected void dispatchDraw(Canvas canvas) { final long drawingTime = getDrawingTime(); final int count = getChildCount(); for (int i = 0; i < count; i++) { drawChild(canvas, getChildAt(i), drawingTime); } } @Override public boolean onInterceptTouchEvent(MotionEvent ev) { mIsScorlling = false; final int action = ev.getAction() & MotionEvent.ACTION_MASK; if (action == MotionEvent.ACTION_CANCEL || action == MotionEvent.ACTION_UP) { mIsScorlling = false; return false; } switch (action) { case MotionEvent.ACTION_DOWN: mActivePointerId = ev.getPointerId(0); mLastMotionX = ev.getX(); mIsScorlling = false; break; case MotionEvent.ACTION_MOVE: final int pointerIndex = ev.findPointerIndex(mActivePointerId); try { final float x = ev.getX(pointerIndex); final float deltaX = mLastMotionX - x; mLastMotionX = x; final float absDeltaX = Math.abs(deltaX); if (absDeltaX > 6) { mIsScorlling = true; } } catch (ArrayIndexOutOfBoundsException e) { } break; } return mIsScorlling; } float downX = -1; @Override public boolean onTouchEvent(MotionEvent ev) { final int action = ev.getAction(); switch (action & MotionEvent.ACTION_MASK) { case MotionEvent.ACTION_DOWN: mLastMotionX = ev.getX(); mActivePointerId = ev.getPointerId(0); downX = mLastMotionX; break; case MotionEvent.ACTION_MOVE: final int pointerIndex = ev.findPointerIndex(mActivePointerId); try { final float x = ev.getX(pointerIndex); final float deltaX = mLastMotionX - x; mLastMotionX = x; if (deltaX > 0) { if (mCurrentViewIndex >= getChildCount() - 1) { return true; } scrollBy((int) deltaX, 0); } else if (deltaX < 0) { if (mCurrentViewIndex <= 0) { return true; } scrollBy((int) deltaX, 0); } else { awakenScrollBars(); } } catch (ArrayIndexOutOfBoundsException e) { } break; case MotionEvent.ACTION_UP: int screenWidth = getWidth(); int whichView = (getScrollX() + (screenWidth / 2)) / screenWidth; whichView = Math.max(0, Math.min(whichView, getChildCount() - 1)); int newX = whichView * getWidth(); int delta = newX - getScrollX(); mScroller.startScroll(getScrollX(), 0, delta, 0, Math.abs(delta) * 2); invalidate(); mCurrentViewIndex = whichView; if (mViewIndexChangeLinstener != null) { mViewIndexChangeLinstener.onIndexChange(whichView); } break; case MotionEvent.ACTION_CANCEL: break; case MotionEvent.ACTION_POINTER_UP: break; } return true; } public interface ViewIndexChangeLinstener { public void onIndexChange(int whichView); } public void setViewIndexChangeLinstener(ViewIndexChangeLinstener linstener) { this.mViewIndexChangeLinstener = linstener; } }